Proteinases of Artemesia longinaris (DECAPODA, PENAEIDAE) fed with different protein sources.

FENUCCI, JORGE LINO; FERNÁNDEZ GIMENEZ, ANALIA VERÓNICA; DÍAZ, ANA CRISTINA; VELURTAS, SUSANA MARIA

Orlando, Florida, USA

Congreso; Aquaculture America 2008; 2008

World Aquaculture Society

PROTEINASES OF Artemesia longinaris (DECAPODA, PENAEIDAE) FED WITH DIFFERENT PROTEIN SOURCES Fenucci, J.L.*, Fernández Gimenez, A.V., Díaz, A.C. and Velurtas, S.M. Facultad de Ciencias Exactas y Naturales Universidad Nacional de Mar del Plata CONICET, Funes 3350 B7602AYL, Mar del Plata, Argentina jfenucci@mdp.edu.ar The prawn Artemesia longinaris has a distribution along the South American coast, from 23°S to 43°S and is one of the most valuable species in the Argentine markets. Proteins in feeds modulate the activity of proteinases in penaeid shrimp, understanding the mode of regulation of midgut gland enzymes is important for rational use of protein feed ingredients using for formulated feeds. The present study describes the effect of different protein sources in formulated feeds on the proteinases activity in the midgut gland of prawn A. longinaris. Three isoproteic and isolipidic formulated feeds were designed containing different amounts of meat and bone meal (feed 2), and soybean meal (feed 3) as substitution of fish meal (feed 1) (protein 38.8%; lipids 7.7%). Feeding trials were carried out on juveniles (1.3±0.51 g initial weight) obtained from coastal waters of Mar del Plata, Argentina (38°S) and held in 150 l glass aquaria (33‰ salinity, 18°C, pH 7, 11:14 h photoperiod). Each feed was tested in three replicate groups of 8 prawns during three weeks. Midgut gland extracts from wild prawns (as control group) and from each treatment, were homogenized and assayed to quantify the proteinase activitiy using azocasein and specific substrates for trypsin and chymotrypsin activity. Classes of proteinase were identified by SDS-polyacrylamide gel electrophoresis; specific inhibitors for trypsin (TLCK), chymotrypsin (TPCK) and serin proteinases (PMSF and SBTI) were used. Total proteolytic activity was not significantly different among the wild prawn and the three treatments (0.29 to 0.44 abs min-1 mg-1). A. longinaris fed with different formulated feeds exhibited differences in trypsin activity related to the control. Chymotrypsin activity was highest for prawns fed with feed supplemented with meat and bone meal. Trypsin and chymotrypsin specific activity (abs min-1 mg-1) was lowest in wild prawns, meanwhile chymotrypsin activity was significant highest in prawns fed with meat and bone meal feed. TLCK and SBTI reduced azocasein hydrolysis between 36.8% (feed 2) and 81.7% (feed 3) (Table 1). TPCK did not decrease hydrolytic activity. Protein and activity bands were compared and common patterns were observed. Six active bands distributed from 16.6 to 53.7 kDawere detected; four trypsins (16.60, 18.20, 21.90, 25.10 kDa) and one chymotrypsin (53.70 kDa) were found. It have been determined an adaptation of trypsin and chymotrypsin to the protein quality in feeds. No clear relationship between different sources of protein in feeds and enzymes were established.